System and method for provisioning virtual circuits in broadband access multiplexing elements

ABSTRACT

A system for provisioning virtual circuits in broadband access multiplexing elements is disclosed. The system manages an algorithm that selects a unique virtual path identifier and virtual circuit identifier for each new multiplexor input from a pool. The system sends commands to connect each new input to the multiplexor output based on the selected virtual path identifier and virtual circuit identifier. The selected virtual path identifier and virtual circuit identifier remain assigned to the input port even if the input connection is later deleted.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to telecommunications systems and, morespecifically, to systems and methods for provisioning resources in abroadband network.

2. Description of the Prior Art

Demand for in-home data and telephony services has grown dramatically inrecent years and is expected to continue to increase. Accordingly,providers of data and telephony services have sought to design anddeploy broadband networks with increased delivery capacity.

One broadband technology that has become particularly popular is digitalsubscriber lines (DSL). DSL offers increased data transfer rates andintegrated telephony and data services using the existing publicswitched telephone network (PSTN), which previously was used exclusivelyfor telephone voice communications.

As the demand for DSL service has grown, service providers have neededto build-out their infrastructure for providing DSL service. Inparticular, service providers have needed to quickly install largenumbers of network elements devoted to providing DSL service. Forexample, service providers have needed to install large numbers ofbroadband access multiplexing elements, which generally include digitalsubscriber line access multiplexors (DSLAM's) and miniature remoteaccess multiplexors (MINIRAM's). Installing, managing, and administeringthese quickly expanding, geographically distributed DSL networks hasbecome increasingly complex, time consuming, and expensive.

One aspect of DSL network maintenance that is very cost and laborintensive is provisioning permanent virtual circuits (PVC's) inbroadband access multiplexing elements. PVC's are permanent, “always on”connections between devices in the DSL network. A physical transmissionpath may be divided into a certain number of virtual paths. Each virtualpath may be further divided into a certain number of virtual channels.Each PVC may be identified by a virtual path identifier (VPI) and avirtual channel identifier (VCI). At a multiplexing element, PVC's maybe connected using VPI's and VCI's. Thus, it is necessary to assign aspecific VPI and a VCI to each of the multiplexor's input ports. This isoften a difficult task because multiplexors may often contain a veryhigh quantity of inputs, and the number of VCI's and VPI's available islimited.

There are several existing methods for assigning a VPI and a VCI to eachmultiplexor input. One existing scheme assigns a VPI and a VCI to eachinput from an algorithm based on the rack, shelf, card and port to whichthat input path is connected. However, this scheme is ineffectivebecause multiplexors often contain too many racks, shelves, cards, andports.

Another existing scheme selects a new VPI and VCI for each “new” input.A “new” input is created each time a new subscriber requests DSLservice. For each new input, an available VPI and VCI is selected from apool of available VPI's and VCI's. When a VPI and a VCI is selected forthe new input they are removed from the pool. If an existing subscriberwishes to have his or her service discontinued, then an existingconnection must be deleted. When an existing connection is deleted theexisting VPI and VCI are placed back in the pool. However, theeffectiveness of this scheme is limited because attempts to delete avirtual circuit cross connection are often unsuccessful. Thus, despiteattempts to delete it, a VPI and VCI may remain assigned to a giveninput even if that input is not actually used by a subscriber. When anew subscriber requests service, he or she may be assigned the same VPIand VCI as the connection that the service provider had previouslyattempted to remove. Therefore, the new subscriber's cross connectionwill fail.

Thus, a need exists in the art for systems and methods for provisioningvirtual circuits in broadband access multiplexing elements that aresuitable for the high quantity of multiplexor inputs and that eliminatethe problem of service failure due to unsuccessful cross connectiondeletion attempts.

SUMMARY OF THE INVENTION

Accordingly, systems and methods for provisioning virtual circuits inbroadband access multiplexing elements are disclosed. Systems andmethods in accordance with the invention are operable in DSL networkscomprising DSL line multiplexor devices such as for example, DSLAM's,and element management systems (EMS's) for managing the operation ofthese same multiplexor devices. As is explained in detail below, a DSLnetwork may comprise a large number of EMS's, with each EMS having alarge number of multiplexors that it is dedicated to managing. The DSLnetwork may also comprise a network management system (NMS) that isresponsible for managing the entire network. The NMS manages individualnetwork elements by sending commands to the EMS dedicated to managingthe particular element.

When a new subscriber requests DSL service, an available input port on amultiplexor is selected to serve as the line termination port for thesubscriber's line. The NMS determines if the selected input port hasbeen previously used. If the selected input port has not been previouslyused, then the NMS assigns to the input port a unique VPI and VCIselected from a pool of available VPI's and VCI's. The pool is unique toeach multiplexor and is maintained by the NMS. The NMS then removes theselected VPI and VCI from the pool. If the selected input port has beenpreviously used, then the NMS assigns to the input port its previous VPIand VCI. The NMS then sends commands to the EMS to connect the selectedinput port's assigned VPI and VCI to the output VPI and VCI.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood after reading thefollowing detailed description of the presently preferred embodimentsthereof with reference to the appended drawings, in which:

FIG. 1 is a high level diagram of an exemplary DSL network;

FIG. 2 is a high level diagram of an exemplary DSL element managementnetwork;

FIG. 3 is a block diagram of a computing device for use in a system inaccordance with an aspect of the invention; and

FIG. 4 is a flowchart of a method for provisioning virtual circuits inbroadband access multiplexing elements.

DETAILED DESCRIPTION

Systems and methods for provisioning virtual circuits in broadbandaccess multiplexing elements in accordance with the invention aredescribed below with reference to FIGS. 1-4. Those skilled in the artwill readily appreciate that the description given herein with respectto those figures is for explanatory purposes only and is not intended inany way to limit the scope of the invention. Throughout the description,like reference numerals will refer to like elements in the respectivefigures.

Generally, applicants have invented systems and methods for provisioningvirtual circuits in broadband access multiplexing elements. When a newsubscriber requests DSL service, an available input port on a broadbandaccess network multiplexing element such as, for example, a DSLAM, isselected to serve as the line termination port for the subscriber'sline. The NMS determines if the selected input port has been previouslyused. If the selected input port has not been previously used, then theNMS assigns to the input port a unique VPI and VCI selected from a poolof available VPI's and VCI's. The pool is unique to each DSLAM and ismaintained by the NMS. The NMS then removes the selected VPI and VCIfrom the pool. If the selected input port has been previously used, thenthe NMS assigns to the input port its previous VPI and VCI. The NMS thensend commands to the EMS to connect the selected input port's assignedVPI and VCI to the output VPI and VCI.

Prior to explaining the details of an illustrative embodiment of theinvention, it is useful to provide a description of a suitable exemplaryenvironment in which the invention may be implemented.

Exemplary DSL Network Environment

1. Exemplary DSL Network

DSL is a technology that converts existing twisted-pair telephone linesinto access paths for multimedia and high-speed data communications. DSLservices promise to dramatically increase the speed of copper wire basedtransmission systems without requiring expensive upgrades to the localloop infrastructure. As used herein, xDSL refers to the numerousvariations of DSL technology using the Bellcore acronyms such as ADSL(Asymmetric DSL), HDSL (high bit-rate DSL), RADSL (rate-adaptive DSL),and the like. New and improved versions of xDSL are in constantdevelopment and the invention is not intended to be limited to anysingle variation of the technology.

Most xDSL signals fall within the frequency range of 4 KHz to 2.2 MHz,with the range of 0 to 4 KHz reserved for the transmission of analogvoice signals for plain old telephone service (POTS). The theoreticalmaximum amount of bandwidth between 4 KHz and 2.2 MHz is almost 70 Mbpsof digital data spectrum. In practice however, only lab test conditionshave ever reached higher than 60 Mbps and currently available productstypically use 2 Mbps to 8 Mbps.

The different types of xDSL technologies may also be categorized aseither symmetric EC xDSL or asymmetric (FDM) xDSL. A first class of ECxDSL includes Integrated Services Digital Network. (ISDN), High-Bit-RateDSL (HDSL), and Single-Line DSL (SDSL). A second class of EC xDSLincludes Asymmetric DSL (ADSL) and Rate Adaptive DSL (RADSL). Themodulation technologies employed with the various types of xDSL include2-binary 1-quaternary (2B1Q) for ISDN and HDSL, carrierless amplitudephase modulation (CAP) for HDSL, SDSL and RADSL, and discrete multi-tonemodulation (DMT) for ADSL and RADSL.

Generally, DMT divides the upstream and downstream bands into smallerindividual or discrete bands. The modems on either end listen to thesediscrete bands as smaller channels within the main upstream ordownstream channel. Often, one of these smaller bands will be disruptedby noise, rendering the information carried within that band useless.Rather than toss away all the information sent at that instant acrossthe entire upstream or downstream band, only that small part is lost andneeds to be retransmitted.

With CAP, the overall amplitude or power of the signal is modulated. Thesignal is not safeguarded against noise and often suffers from lostinformation, which accounts in part for the lower transmission speeds ofCAP-based DSL technologies. With amplitude modulation, there is alsomore loss over longer ranges. The benefits of CAP over DMT are that itis simpler in design and therefore cheaper, requires less power, andgenerates less heat. Both power consumption and heat are serious factorswhen it comes to housing many of these systems together (as in a centraloffice). DMT however, often provides the best results and maintains thefull bandwidth at its maximum range of 18,000 feet. CAP signals degradequickly after 10,000 feet.

Typical xDSL systems are implemented as follows. At the customerpremises a splitter is provided which separates the xDSL signals (i.e.,digital data signals) from the POTS analog voice signals. The mainpurpose of the splitter is to shield ordinary telephones from the highfrequency xDSL signals that can have disastrous effects on the telephoneor human ear. The data line from the splitter connects to an xDSL modemand the analog line connects to the telephone. With xDSL Lite and someother product models, there is no external splitter or it is combinedinto the xDSL modem unit. An Ethernet line will usually link the xDSLmodem to the customer premises PC.

The twisted pair from the customer premises connects to an xDSL accessmultiplexor such as, for example a DSLAM, typically located at theincumbent local exchange carrier (ILEC) central office (CO). The twistedpair from the customer premise may also pass through a neighborhoodwiring distribution frame, which is a central point where the wire pairsfrom several customer premises come together, and/or an ILEC remoteterminal before reaching the CO. Typically, a DSLAM is a multi-moduleunit that houses many CO-side xDSL modems within a single shelf muchlike the analog modern racks of today. At the DSLAM the voice and datalines are split out along separate paths. The digital data signal goesinto either an ATM concentrator or an Internet Protocol router. Theanalog voice signals are connected to the CO phone switch. Thus, thedigital data packets go through the router out to the Internet, and theanalog voice signals go through the phone switch and into the publicswitched telephone network.

ADSL is one particularly promising and popular form of xDSL. ADSL cantransmit up to 6 Mbps to a subscriber, and as much as 832 kbps or morein both the downstream and upstream directions. Such rates expandexisting access capacity by a factor of 50 or more without the need toinstall new wiring or cabling. An ADSL circuit connects an ADSL modem oneach end of a twisted-pair telephone line, creating three informationchannels—a high speed downstream channel, a medium speed duplex channel,depending on the implementation of the ADSL architecture, and a POTS orISDN channel. The POTS/ISDN channel is split off from the digital modemby filters, thus guaranteeing uninterrupted POTS/ISDN, even if ADSLfails. The high speed channel ranges from 1.5 to 6.1 Mbps, while duplexrates range from 16 to 832 kbps. Each channel can be submultiplexed toform multiple, lower rate channels, depending on the system.

ADSL modems provide data rates consistent with North American andEuropean digital hierarchies and can be purchased with various speedranges and capabilities. The minimum configuration provides 1.5 or 2.0Mbps downstream and a 16 kbps duplex channel; others provide rates of6.1 Mbps and 64 kbps duplex. Products with downstream rates up to 8 Mbpsand duplex rates up to 640 kbps are currently available. ADSL modemsalso can accommodate ATM transport with variable rates and compensationfor ATM overhead, as well as IP protocols. Downstream data rates dependon a number of factors, including the length of the copper line, itswire gauge, presence of bridged taps, and cross-coupled interference.Line attenuation increases with line length and frequency, and decreasesas wire diameter increases.

FIG. 1 shows an exemplary ADSL based broadband access architecture 100.In order for an IP enabled device (e.g., personal computer 103 in home102 a) to establish a service session with a source on the Internet 115,the IP enabled device first establishes an access session with an OpenSystems Interconnection (OSI) model layer 2/3 communications element(e.g., router 114) in an Internet service provider (ISP) network (e.g.,ISP network 113) through an asynchronous transfer mode (ATM) basedbroadband access network (e.g., broadband access network 101) with abroadband access device (e.g., DSL modem 104) connected to the localloop. (e.g., link 106 a). An IP client (not shown) on the IP enableddevice secures an IP address from the ISP using Dynamic HostConfiguration Protocol (DHCP) from a DHCP server (not shown) incommunication with the ISP's router. The DHCP server temporarilyallocates or leases a unique IP address to the IP client. The IP clientmay now obtain IP based services available on the ISP network and beyondby sending and receiving packets to and from the ISP's router throughthe broadband access network. Sources on the Internet 115 are reached byutilizing a communications link between the ISP network and the Internet115 (e.g., communications link 117).

In addition to the layer 2 communications elements (e.g., asynchronoustransfer mode (ATM) switches 108 and 109), layer 2/3 communicationselements also form a part of broadband access network 101. Specifically,a plurality of layer 2/3 communications elements (e.g., ingressbroadband gateways 120 a-n) reside after various layer 2 communicationselements (e.g., ATM Switch 108) lying near ingress points for accessdevice IP traffic (e.g., IP traffic from personal computer 103), and aplurality of layer 2/3 communications elements (e.g., egress broadbandgateway 121 a) reside after layer 2 communications elements (e.g., ATMSwitch 109) lying near egress points for access device IP trafficdestined for ISP networks (e.g., ISP network 113) linked to broadbandaccess network 101. In exemplary network 100, ATM switch 108 maycomprise, for example, a Lucent CBX 500 multiservice WAN switch, and ATMswitch 109 may comprise, for example, a Lucent GX 550 multiservice WANswitch. Ingress and egress broadband gateways 120, 121 comprise, forexample, Nortel 5000 Broadband Service Nodes.

Each of the layer 2/3 communications elements in broadband accessnetwork 101 supports the creation of layer 3 communications sessionsbetween various communications elements within and without network 101using layer 3 protocols such as IP. The layer 2/3 communicationselements also support the creation of virtual layer 2 communicationssessions or “virtual PVCs (vPVCs)” using one or more of the followingprotocols: Point-to-Point Protocol (PPP) over Ethernet (PPPoE), PPP overATM (PPPoA), Layer 2 Tunneling Protocol (L2TP), Point-to-Point TunnelingProtocol (PPTP), and/or Switched Multimegabit Data Service (SMDS)Interface Protocol (SIP). A PVC is a “permanent” virtual circuit andprovides an “always on” connection whether the subscribers is activelyusing it or not. Thus, a series of three layer 2 virtual PVCs (e.g.,vPVC1 a 125 a, vPVC2 a 126 a, and vPVC3 a 127 a) extend from an accessdevice (e.g., ADSL modem 104) to an ISP (e.g., ISP network 113) throughbroadband access network 101 (versus having a single layer 2 PVCextending from an access device to an ISP as in other broadband accessnetworks).

The first layer 2 vPVC (e.g., vPVC1 a 125 a) extends from an accessdevice (e.g., ADSL modem 103) to one of the ingress layer 2/3communications elements (e.g., ingress broadband gateway 120 a), and isthe only vPVC devoted exclusively to a single IP subscriber. Typicallythe first layer 2 vPVC is a user authenticated PPP session. In oneembodiment of the network 101 the first layer 2 vPVC is a userauthenticated PPPoE session where the IP enabled device (or the operatorthereof) supplies a username and domain (e.g., “user1@domain1”). Basedon the domain provided, the first layer 2/3 communications elementestablishes a virtual layer 2 connection using L2TP over the remainingtwo layer 2 vPVCs to reach the appropriate ISP and the ISP provides theIP enabled device an IP address for obtaining IP based services. Thismodel allows for the creation of access sessions with different ISPsdepending on the domain provided by the IP enabled device. This modelalso allows IP services to be billed to a particular user on a peraccess session basis.

The second vPVC (e.g., vPVC2 a 126 a) extends from the foregoing ingresslayer 2/3-communications element (e.g., Ingress Broadband Gateway 120 a)to one of the egress layer 2/3 communications elements (e.g., EgressBroadband Gateway 121 a). Through the use of a tunneling protocol suchas L2TP, PPP aggregation occurs at the layer 2/3 ingress communicationselement and the multiple PPP communications sessions between accessdevices (e.g., access devices in homes 102 b-n) served by the ingresslayer 2/3 communications element are funneled into the second vPVC. Thethird vPVC (e.g., vPVC3 a 127 a) extends from the foregoing egress layer2/3 communications element (e.g., Egress Broadband Gateway 121 a) to thelayer 2/3 communications element in the ISP network. In this embodimentof the invention the layer 2/3 communications element in the ISP networkis an LNS capable router (e.g., layer 2/3 communications element 114).Again, through the use of a tunneling protocol such as L2TP, PPPaggregation occurs at the egress layer 2/3 communications element andthe multiple PPP communications sessions from multiple L2TP IBG tunnelsare concentrated onto a single L2TP tunnel by the egress broadbandgateway and are funneled into the third virtual PVC. The third virtualPVC delivers a large (doubly aggregated) L2TP tunnel to the LNS router114 where the PPP sessions are terminated and IP packets are once againrouted normally.

As shown in FIG. 1, each twisted wire pair from customer premises 102a-n housing an xDSL modem 104 connects to a multiplexor device such as,for example DSLAM 107 or MiniRAM 140. Furthermore, a connection fromMiniRAM 140 terminates in DSLAM 107. In exemplary network 100, DSLAM 107may be, for example, an Alcatel 7300 DSL Access Line Multiplexor.Generally, a cross connection must be completed between the input portsof DSLAM 107 and the output port of DSLAM 107. This connection iscompleted using the unique VPI's and VCI's assigned to each input portand to the output port. Systems and methods for provisioning VPI's andVCI's in broadband access multiplexing elements are described below.

2. Provisioning Virtual Circuits in Broadband Access MultiplexingElements

FIG. 2 depicts an illustrative DSL network management system 200 inwhich systems and methods provisioning virtual circuits in broadbandaccess multiplexing elements in accordance with the invention mayoperate. As shown, system 200 comprises at least one network managementsystem (NMS) 202, a plurality of element managers (EMSs) 201 a-201 m,DSLAMs 107 a-n forming a portion of broadband access network 101,MiniRAMs 140 a-n also forming a portion of broadband access network 101,and a plurality of communication paths or links 202 a-n, 203 a-m, 204a-m between the NMS, EMSs, DSLAMs, and MiniRAMs. NMS 202 coordinates theoperation of nodes, elements, objects, cards, physical links, equipment,and the like, within network management system 200. DSLAMs 107 a-n andMiniRAMs 140 a-n comprise managed elements within network managementsystem 201. EMSs 201 a-m comprise intermediaries between NMS 202 and thebroadband network elements including DSLAMs 107 a-n and MiniRAMs 140a-n. As an intermediary, the EMSs interpret messages, such as simplenetwork management protocol (SNMP) messages, to and from nodes innetwork management system 201. In one embodiment of the inventioncommunication between the NMS 202 and the EMSs 201 a-m is via X.25,serial, TCP/IP, or UDP/IP connection while communication between theEMSs 201 a-m and the DSLAMs 107 a-n is via SNMP over UDP/IP. In anillustrative embodiment of system 200, NMS 202 comprises, for example,an Alcatel 5620 Network Manager, EMSs 201 a-m comprise, for example,Alcatel 5526 Access Management Systems, DSLAMs 107 a-n comprise, forexample, Alcatel 7300 DSL Subscriber Access Platform.

NMS 202 manages the algorithm that provisions virtual circuits inDSLAM's 107 a-n. NMS 202 selects a VPI and VCI for each new input toDSLAM's 107 a-n and sends commands to EMS's 201 a-m to connect the VPIand VCI of each new input to DSLAM's 107 a-n to the output of DSLAM's107 a-n.

NMS 202 may be implemented on a generic computing system such as isshown in FIG. 3. As shown, computing device 320 includes processing unit322, system memory 324, and system bus 326 that couples various systemcomponents including system memory 324 to the processing unit 322. Thesystem memory 324 might include read-only memory (ROM) and random accessmemory (RAM). The system might further include hard-drive 328, whichprovides storage for computer readable instructions, data structures,program modules and other data. A user may enter commands andinformation into the computer 320 through input devices such as akeyboard 340 and pointing device 342. A monitor 344 or other type ofdisplay device is also connected to the system for output.Communications device 343, which may be for example a TCP/IP enabledevice, provides for communications in system 200. Processor 322 can beprogrammed with instructions to interact with other computing systems soas to perform the algorithms described below with reference to FIG. 4.The instructions may be received from network 200 or stored in memory324 and/or hard drive 328. Processor 322 may be loaded with any one ofseveral computer operating systems such as Windows NT, Windows 2000,Linux, and the like. Those skilled in the art recognize that while NMS202 is illustrated as a single desktop computing system, a network ofcomputing systems and/or other computing devices such as for example,laptop and handheld computing devices might be employed.

FIG. 4 is a flowchart of a method for provisioning virtual circuits inbroadband access multiplexing elements. When a new subscriber requestsDSL service, NMS 202 selects an available input port on one of DSLAM's107 a-n to serve as the line termination port for the subscriber's lineat step 410. At step 412, NMS 202 determines if the selected input porthas been previously used. If the selected input port has not beenpreviously used, then, at step 414, NMS 202 assigns to the input port aunique VPI and VCI selected from a pool of available VPI's and VCI's.The pool is unique to each DSLAM 107 a-n and is maintained by NMS 202.At step 416, NMS 202 removes the selected VPI and VCI from the pool.

If the selected input port has been previously used, then, at step 418,NMS 202 assigns to the input port its previous VPI and VCI. At step 420,NMS 202 sends commands to dedicated EMS 201 a-m to complete a connectionbetween the selected DSLAM input and the DSLAM output.

If an existing subscriber's DSL service is canceled, the subscriber'sconnection is deleted. However, the VPI and VCI of the subscriber'sinput port remained assigned to that port and are not placed back in thepool of available VPI's and VCI's. Thus, a new subscriber's line on adifferent input port cannot be assigned the same VPI and VCI as thedeleted connection. This eliminates the problem of service failure dueto unsuccessful cross connection deletion attempts.

Thus, systems and methods for provisioning virtual circuits in broadbandaccess multiplexing elements have been disclosed. These novel systemsand methods comprise selecting a specific VPI and VCI for each newmultiplexing element input from a pool of available VPI's and VCI's.Furthermore, these systems and methods eliminate the problem of servicefailure due to unsuccessful cross connection deletion attempts because apermanent VPI and VCI is assigned to each input port of the multiplexingelement.

Those skilled in the art understand that computer readable instructionsfor implementing the above-described processes, such as those describedwith reference to FIG. 4, can be generated and stored on one of aplurality of computer readable media such as a magnetic disk or CD-ROM.Further, a general purpose computer such as that described withreference to FIG. 3 may be arranged with other similarly equippedcomputers in a network, and may be loaded with computer readableinstructions for performing the above described processes. Specifically,referring to FIG. 3, microprocessor 322 may be programmed to operate inaccordance with the above-described processes.

While the invention has been described and illustrated with reference tospecific embodiments, those skilled in the art will recognize thatmodification and variations may be made without departing from theprinciples of the invention as described above and set forth in thefollowing claims. For example, while the invention has been described inconnection with provisioning of virtual circuits in DSLAM's, the systemsand methods may be employed to plan other types of DSL multiplexingdevices as well. Accordingly, reference should be made to the appendedclaims as indicating the scope of the invention.

1. A method for provisioning virtual circuits in broadband accessmultiplexing elements, comprising: selecting a multiplexing elementinput port for use determining if the selected input port has beenpreviously selected for use; if the input port has not been previouslyselected, then assigning to the input port a virtual path identifier anda virtual circuit identifier selected from a pool of available virtualpath identifiers and available virtual circuit identifiers; and if theinput port has been previously selected, then assigning to the inputport its previously assigned virtual path identifier and virtual circuitidentifier.
 2. The method of claim 1, wherein the step of assigning tothe input port a virtual path identifier and a virtual circuitidentifier selected from a pool comprises removing the assigned virtualpath identifier and virtual circuit identifier from the pool after ithas been assigned.
 3. The method of claim 1, further comprising the stepof sending commands to a multiplexing element management device tocomplete a connection between the selected multiplexing element inputport and the multiplexing element output port using the virtual pathidentifier and virtual circuit identifier assigned to each port.
 4. Themethod of claim 1, wherein said pool of available virtual pathidentifiers and available virtual circuit identifiers is unique to eachmultiplexing element.
 5. The method of claim 1, wherein said broadbandaccess multiplexing element comprises a digital subscriber line accessmultiplexor.
 6. The method of claim 1, wherein said input port comprisesa port receiving a connection from one of a digital subscriber linemodem or a miniature remote access multiplexer.
 7. The method of claim1, wherein said pool of available virtual path identifiers and availablevirtual circuit identifiers is maintained by a network managementsystem.
 8. A computer readable medium having computer executableinstructions recorded thereon for performing the method recited inclaim
 1. 9. A system for provisioning virtual circuits in broadbandaccess multiplexing elements, comprising: a processor operative toexecute computer executable instructions; and a memory having storedtherein computer executable instructions for performing the followingsteps: selecting a multiplexing element input port for use; determiningif the selected input port has been previously selected for use; if theinput has not been previously selected, then assigning to the input porta virtual path identifier and a virtual circuit identifier selected froma pool of available virtual path identifiers and available virtualcircuit identifiers; and if the input port has been previously selected,then assigning to the input port its previously assigned virtual pathidentifier and virtual circuit identifier.
 10. A system for provisioningvirtual circuits in broadband access multiplexing elements, comprising:a means for selecting a multiplexing element input port for use; a meansfor determining if the selected input port has been previously selectedfor use; and a means for assigning to the input port a virtual pathidentifier and a virtual circuit identifier selected from a pool ofavailable virtual path identifiers and available virtual circuitidentifiers if the input has not been previously selected; and a meansfor assigning to the input port its previously assigned virtual pathidentifier and virtual circuit identifier if the input port has beenpreviously selected.